Reductase activity of aldehyde oxidase toward the carcinogen N-hydroxy-2-acetylaminofluorene and the related hydroxamic acids.

Liver aldehyde oxidase (EC 1.2.3.1) was capable of reducing N-arylacetohydroxamic acids, N-hydroxy-2-acetyl-aminofluorene, N-hydroxy-4-acetylaminobiphenyl and N-hydroxyphenacetin, to the corresponding amides in the presence of an electron donor of the enzyme under anaerobic conditions. When supplemented with an electron donor of the enzyme, a significant reduction of N-hydroxy-2-acetylaminofluorene occurred, which was sensitive to an inhibitor of the enzyme. These observations were made with cytosolic fractions prepared from the livers of rabbits, guinea pigs, rats and mice.